Speaking to reporters Wednesday, press secretary Jay Carney addressed details of the book, Duty: Memoirs of a Secretary at War. It isscheduled for release Jan. 14, but its contents have already been widely reported in recent days.

"The president greatly appreciates Secretary Gates' service," Carney said, adding that Gates "was part of a team here that helped bring an end to the Iraq War, that helped cement a far superior and improved policy in Afghanistan."

In the book, the former defense secretary describes the commander in chief as "a man of personal integrity," but says both President Obama and Vice President Joe Biden were suspicious and distrustful of senior military leaders. He singled out Biden for "poisoning the well" against the top brass.

Carney said the president selected a Cabinet and advisers to be a team of rivals who would give frank assessments of the situation.

"When you pick a team of rivals, you do so in part because you expect competing points of view and competing opinions," he said. "That's very much what the president expects in foreign policy and domestic policy, and that's what he gets."

The press secretary defended Biden, saying the vice president "is a key adviser on national security matters and domestic policy matters," whose counsel the president "greatly values." Biden "is not a person that this president chose simply to affirm what others are thinking."

According to reports in The New York Times and The Washington Post, Gates writes in his memoir that Obama "can't stand" Afghan President Hamid Karzai.

"I wouldn't agree with that," Carney said.

"I think the issues here are not about personalities, they are about policies," he told reporters. "And, the decisions the president makes about sending and keeping military forces, American men and women in uniform, in Afghanistan have to do with U.S. national security interests, not those kinds of issues."

On the issue of trust and the military leadership, he said: "The president, the vice president, everyone in this building who has ever served and worked on these matters has enormous respect for our men and women in uniform and that includes all of the president's top military advisers."

Carney said it should come as no surprise that the president's aim was to exit Afghanistan, something the administration campaigned on and has worked toward from the beginning.

"It is well known that the president has been committed to achieving the mission of disrupting, dismantling and defeating al-Qaida while also ensuring that we have a clear path for winding down the war, which will end this year," he said.